Answer:
The difference between iconography and iconology is that iconography is the meaning of symbols and images in a piece of work. However, iconology is the study of the meaning contained within a piece of art in a broader cultural or artistic context. While symbolic meaning is present in iconology, it is the focus of iconography. For example, while the symbolic meaning of a piece could be a figure of religion, the broader context could be a rise in a certain religion of the environment around the artist.
To your second question :)